Sperm webs are temporary mats of silk that mature males make in preparation for mating. They deposit sperm (which comes from an opening under the abdomen) into the sperm web and then draw the sperm up into their palpal emboli. (When they mate, they insert their emboli into the female's epigyne.) If a mature male has stopped making sperm webs, he's unlikely to father any offspring even if paired with a female.
Thank you. Very helpful and has cleared up some of my own misconceptions. I thought sperm webs were a secondary method of mating, where a female would go to the web and absorb the sperm or something. Ha ha.Sperm webs are temporary mats of silk that mature males make in preparation for mating. They deposit sperm (which comes from an opening under the abdomen) into the sperm web and then draw the sperm up into their palpal emboli. (When they mate, they insert their emboli into the female's epigyne.) If a mature male has stopped making sperm webs, he's unlikely to father any offspring even if paired with a female.
The charging behavior is easy to spot if you catch it: the palps move up and down repeatedly against the webbing.
Sperm webs don't look like regular webbing, and usually the web is mostly destroyed after it's no longer needed. So unless you catch them in the act of charging their palps, you'll probably just see little stringy remains of the sperm webs.
Here is a photo by @boina of male creating a sperm web:
This post by @cold blood shows what the remnants of a sperm web look like compared to regular webbing.
Male spiders are kind of weird in that the place where the sperm is generated is far apart from the apparatus they use to deliver sperm to the female, so they need this intermediate step.
It's like a weird "I'll save that for later." type of thing. Really fascinating.
Males actually have special microscopic spinnerets (the epiandrous fusillae) near the ventral furrow that are used just to make their sperm webs. Sometimes you can spot the discolored patch of hairs around the fusillae when examining the tarantula ventrally, which is a way to sex an immature male when no molt is available.
Tfw you're more biologically complex but are smaller, can be overpowered by females and die quicker.
The epiandrous fusillae (spinnerets) only spin the silk that is used to construct the sperm web. The actual sperm is produced in the testes.
T's have testicles?! Wow! Okay now I'm- oh wait they're not like human ones. My guess is they're internal?
Yes, the testes are internal, located within the abdomen. (No, they don't have a penis.)
The pedipalps are inserted into the female's lid thing so I guess they do what the penis does, kind of?
It's performing a similar function (inseminating the female), but it's not technically a penis.
It seems very complex. Also, why is it so risky? Why do the females kill the male sometimes?
This is an excerpt about post-coital cannibalism from p. 248 of Biology of Spiders by Rainer Foelix (internal citations omitted).
I think as far as tarantulas are concerned, it's probably common for the males to escape in the wild. In captivity, cannibalism may be higher (without human intervention), because the male has nowhere to run.Biology of Spiders said:
That's weird. I never thought about them being in an enclosure increasing death percentages because the males can't run... I should have figured that out.
So when people say that some Tarantula species are harder to pair than others it's not because some species are more likely to eat the male?
Not always, sometimes yes...there are other factors to consider, such as just being reluctant to initiate breeding, or having extremely long courtship.
I see
